Sleeper for railways, tramways, and the like of cement-asbestos with metallic reinforcements



Allg. 15, 1939. A. MAZZA 2,169,704

SLEEPER FOR RAILwAYs, TRAMWAYS. AND THE LIKE oF CEMENT-ASBESTOS WITH METALLIC REINFORCEMENTS Filed Sept. 22, 1936 a, F744 a I 5 747.5,

a INVENTOR:

ADOLFO MAZZA ATToRNEx/ Patented Aug. 15, 1939 UNITED STATES PATENT FFICE Adolfo Mazza, Genoa, Italy Application September 22, 1936, Serial No. 101,905 In Italy April 25, 1936 4 Claims.

The present invention involves replacing wooden, iron or reinforced concrete sleepers, that are being used at present and that have a great tendency to deteriorate under the action of the Weather, and of the passage of trains, by Eternit (cement-asbestos) sleepers conveniently reinforced.

It is well known that Eternit is composed of very thin layers of cement and asbestos in libres, that are superposed, uniform, strongly compressed, incorporated with each other and perfectlycompact, insensible to the deleterious action of weather, of frost and of summer heat: they are inoxidizable and now-decaying and also not subject to attack by insects, including white ants. Consequently Eternit sleepers can be eX- pected to last indefinitely, and at any rate much longer than the wooden, iron and reinforced concrete sleepers that are being used at present.

Besides, cement-asbestos Eternit sleepers are not so stiff as iron sleepers or reinforced concrete sleepers and cement-asbestos .Eternit offers to traction a resistance equal to six times the resistance offered by cement concrete and in respect to compression Eternit attains a breaking load equal to six times that of the cement conglomerate of reinforced concrete.

The accompanying drawing shows an instance of the practical execution of this invention:

Fig. 1 shows, for instance, the cross section of this cement-asbestos sleeper with a metallic reinforcement. It is assumed that this section is taken parallel and adjacent one edge of the rails.

Fig. 2 shows a cross section of the same sleeper, made transversely across the middle of the same.

Fig. 3 shows a portion of the longitudinal section of the same sleeper in correspondence with one of the bolts for xing the rails.

Figures 4 and 5 are plan views showing an example of the disposition given to the iron bars that provide the metallic reinforcement respectively in the upper and in the lower portion of abovesaid sleeper, made of twenty or more successive and superposed iiat layers of cementasbestos Eternit, about 6 mm. thick in the uncompressed sheets, strongly compressed and bonded to each other.

Fig. 6 shows in `a schematic way and Fig. 7 is a section on line 1--1 of Fig. 6 showing an example of flat iron with holes for the small nails or anchoring spikes for xing the iron itself in the cement-asbestos layers between which the bars forming the metallic reinforcement of the sleeper are laid.

(Cl. 23S- 91) Figures 8, l0 and l2 show in a schematic way and Figs. 9, 11 and 13 are sections on lines 9 9, II-I I, and I3--I3 respectively, in Figs. 8, 10 and 12 showing three examples of indentations respectively on flat iron bars, on round iron bars g and on square iron bars.

The metallic reinforcement of this sleeper as indicated in Figs. 4 and 5, may consist of flat iron bars (a, a the upper ones, b, b' the lower ones) conveniently drilled in d at lgiven intervals for inserting into the holes spikes or nails c for anchoring these iron bars to the underlying layers of cement-asbestos Eternit, in order to prevent the fiat iron bars from slipping or sliding with respect to the aforesaid layers. The aforementioned bars can also be conveniently indented for anchoring them in the cement-asbestos and, generally speaking, the reinforcement of these sleepers can be formed in any way with suitable metallic ribs, conveniently anchored and fixed in the sleeper consisting of various superposed and compressed layers of cement-asbestos Eternit, but in any case the reinforcement is embedded in the cement-asbestos.

In respect also of the arrangement of the successive layers of cement-asbestos Eternit, they must be horizontally arranged, for instance, as Figures 1, 2 and 3 show in a schematic Way.

'Ihe indented iron bars (Figures 6, '7, 8, 9, 10, 1.1, 12 and 13), instead of being formed of ilat iron, can be made by round or square iron bars on which alternate notches or indentations g have been previously made so as to be able to anchor them in the cement-asbestos Eternit sheets and consequently to prevent them from eventually sliding between the sheets themselves.

To facilitate the connection of the various layers of cement-asbestos in a soft state, it may be convenient to insert avery liquid cement between.

The metallic reinforcement has the following purposes:

1. To keep united the pieces in which the sleeper in question might be divided in the event of a transversal rupture of the cement-asbestos Eternit sheets.;

2. And chiefly to help the cement-asbestos Eternit to resist traction strains simultaneously with resistance to flexure strains.

To this end the metallic reinforcement is distributed in two or more planes so as to be chiey found in those points of the sleepers where tension will occur, that is chiefly in the lower portion in correspondence of the rails and in` the upperv portion towards the medium section of the sleepers, precisely as Figures 1, 2, 4 and 5 herewith show as an instance in a schematic way.

Froml Figures 4 and 5 one can also see how the two different reinforcements (lateral reinforcements and medial reinforcements), lower and upper reinforcements, are disposed in such a way that they superpose for a certain distance, so as to ensure the continuity of the metallic reinforcement in every sleeper from one end to the other.

Besides, Figures 1 and 3 show clearly the disposition of some metallic rings e placed in the holes through which bolts f are to pass for xing the rails. These metallic rings have the scope of preventing a direct contact between the bolt and the Eternit material.

Of course, the details relating to construction and to form can be varied in practice without coming therefore out of the range of the present invention, both in regard to the external profile of the sleeper and to the measurement and disposition of the various parts that compose it and of the iron pieces that are used for the reinforcement and for fixing.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:

1. In a reinforced sleeper for railways and the like, including a plurality of distinct superposed cement-asbestos sheets having longitudinally disposed metal reinforcing bars inserted therein, the

feature of having cementing material between said distinct sheets and these sheets closely adherent under initially highly compressed and permanently compacted and bonded condition.

2. In a reinforced sleeper for railways and the like, including a plurality of superposed cementasbestos sheets having longitudinally disposed metal reinforcing bars inserted therein, the combination of an initially fluid bonding cement forming the cementing material interposed between the successive sheets and the feature of having said sheets closely adherent under initially highly compressed and permanently compacted and bonded condition.

3. The method of making a laminated railway sleeper or tie, which consists in making sheets of cement with longitudinally arranged asbestos bre, superposing a plurality of said sheets and inserting longitudinal metal reinforcing bars at spaced intervals between certain of said sheets, and bonding and compressing said assemblage of sheets and reinforcing bars under Very heavy pressure to compact the same into a bonded composite whole.

4. 'I'he method according to claim 3, which includes also the step of introducing between each pair of adjacent sheets a bonding cement of more fluid character than the cement composing said sheets and subsequently proceeding to temporarily high compression of the sheet assemblage to form the sleeper.

ADOLFO MAZZA. 

